Syntax:
CHANGE REPLICATION SOURCE TO option [, option] ... [ channel_option ]

option: {
    SOURCE_BIND = 'interface_name'
  | SOURCE_HOST = 'host_name'
  | SOURCE_USER = 'user_name'
  | SOURCE_PASSWORD = 'password'
  | SOURCE_PORT = port_num
  | PRIVILEGE_CHECKS_USER = {NULL | 'account'}
  | REQUIRE_ROW_FORMAT = {0|1}
  | REQUIRE_TABLE_PRIMARY_KEY_CHECK = {STREAM | ON | OFF | GENERATE}
  | ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS = {OFF | LOCAL | uuid}
  | SOURCE_LOG_FILE = 'source_log_name'
  | SOURCE_LOG_POS = source_log_pos
  | SOURCE_AUTO_POSITION = {0|1}
  | RELAY_LOG_FILE = 'relay_log_name'
  | RELAY_LOG_POS = relay_log_pos
  | SOURCE_HEARTBEAT_PERIOD = interval
  | SOURCE_CONNECT_RETRY = interval
  | SOURCE_RETRY_COUNT = count
  | SOURCE_CONNECTION_AUTO_FAILOVER = {0|1}
  | SOURCE_DELAY = interval
  | SOURCE_COMPRESSION_ALGORITHMS = 'algorithm[,algorithm][,algorithm]'
  | SOURCE_ZSTD_COMPRESSION_LEVEL = level
  | SOURCE_SSL = {0|1}
  | SOURCE_SSL_CA = 'ca_file_name'
  | SOURCE_SSL_CAPATH = 'ca_directory_name'
  | SOURCE_SSL_CERT = 'cert_file_name'
  | SOURCE_SSL_CRL = 'crl_file_name'
  | SOURCE_SSL_CRLPATH = 'crl_directory_name'
  | SOURCE_SSL_KEY = 'key_file_name'
  | SOURCE_SSL_CIPHER = 'cipher_list'
  | SOURCE_SSL_VERIFY_SERVER_CERT = {0|1}
  | SOURCE_TLS_VERSION = 'protocol_list'
  | SOURCE_TLS_CIPHERSUITES = 'ciphersuite_list'
  | SOURCE_PUBLIC_KEY_PATH = 'key_file_name'
  | GET_SOURCE_PUBLIC_KEY = {0|1}
  | NETWORK_NAMESPACE = 'namespace'
  | IGNORE_SERVER_IDS = (server_id_list),
  | GTID_ONLY = {0|1}
}

channel_option:
    FOR CHANNEL channel

server_id_list:
    [server_id [, server_id] ... ]

CHANGE REPLICATION SOURCE TO changes the parameters that the replica
server uses for connecting to the source and reading data from the
source. It also updates the contents of the replication metadata
repositories (see
https://dev.mysql.com/doc/refman/8.4/en/replica-logs.html).

CHANGE REPLICATION SOURCE TO requires the REPLICATION_SLAVE_ADMIN
privilege (or the deprecated SUPER privilege).

Options that you do not specify on a CHANGE REPLICATION SOURCE TO
statement retain their value, except as indicated in the following
discussion. In most cases, there is therefore no need to specify
options that do not change.

Values used for SOURCE_HOST and other CHANGE REPLICATION SOURCE TO
options are checked for linefeed (\n or 0x0A) characters. The presence
of such characters in these values causes the statement to fail with an
error.

The optional FOR CHANNEL channel clause lets you name which replication
channel the statement applies to. Providing a FOR CHANNEL channel
clause applies the CHANGE REPLICATION SOURCE TO statement to a specific
replication channel, and is used to add a new channel or modify an
existing channel. For example, to add a new channel called channel2:

CHANGE REPLICATION SOURCE TO SOURCE_HOST=host1, SOURCE_PORT=3002 FOR CHANNEL 'channel2';

If no clause is named and no extra channels exist, a CHANGE REPLICATION
SOURCE TO statement applies to the default channel, whose name is the
empty string (""). When you have set up multiple replication channels,
every CHANGE REPLICATION SOURCE TO statement must name a channel using
the FOR CHANNEL channel clause. See
https://dev.mysql.com/doc/refman/8.4/en/replication-channels.html for
more information.

For some of the options of the CHANGE REPLICATION SOURCE TO statement,
you must issue a STOP REPLICA statement prior to issuing a CHANGE
REPLICATION SOURCE TO statement (and a START REPLICA statement
afterwards). Sometimes, you only need to stop the replication SQL
(applier) thread or the replication I/O (receiver) thread, not both:

o When the applier thread is stopped, you can execute CHANGE
  REPLICATION SOURCE TO using any combination that is otherwise allowed
  of RELAY_LOG_FILE, RELAY_LOG_POS, and SOURCE_DELAY options, even if
  the replication receiver thread is running. No other options may be
  used with this statement when the receiver thread is running.

o When the receiver thread is stopped, you can execute CHANGE
  REPLICATION SOURCE TO using any of the options for this statement (in
  any allowed combination) except RELAY_LOG_FILE, RELAY_LOG_POS,
  SOURCE_DELAY, or SOURCE_AUTO_POSITION = 1 even when the applier
  thread is running.

o Both the receiver thread and the applier thread must be stopped
  before issuing a CHANGE REPLICATION SOURCE TO statement that employs
  SOURCE_AUTO_POSITION = 1, GTID_ONLY = 1, or
  ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS.

You can check the current state of the replication applier thread and
replication receiver thread using SHOW REPLICA STATUS. Note that the
Group Replication applier channel (group_replication_applier) has no
receiver thread, only an applier thread.

CHANGE REPLICATION SOURCE TO statements have a number of side-effects
and interactions that you should be aware of beforehand:

o CHANGE REPLICATION SOURCE TO causes an implicit commit of an ongoing
  transaction. See
  https://dev.mysql.com/doc/refman/8.4/en/implicit-commit.html.

o CHANGE REPLICATION SOURCE TO causes the previous values for
  SOURCE_HOST, SOURCE_PORT, SOURCE_LOG_FILE, and SOURCE_LOG_POS to be
  written to the error log, along with other information about the
  replica's state prior to execution.

o If you are using statement-based replication and temporary tables, it
  is possible for a CHANGE REPLICATION SOURCE TO statement following a
  STOP REPLICA statement to leave behind temporary tables on the
  replica. A warning (ER_WARN_OPEN_TEMP_TABLES_MUST_BE_ZERO
  (https://dev.mysql.com/doc/mysql-errors/8.4/en/server-error-reference
  .html#error_er_warn_open_temp_tables_must_be_zero)) is issued
  whenever this occurs. You can avoid this in such cases by making sure
  that the value of the Replica_open_temp_tables system status variable
  is equal to 0 prior to executing such a CHANGE REPLICATION SOURCE TO
  statement.

o When using a multithreaded replica (replica_parallel_workers > 0),
  stopping the replica can cause gaps in the sequence of transactions
  that have been executed from the relay log, regardless of whether the
  replica was stopped intentionally or otherwise. In MySQL 8.4, these
  can be resolved using GTID auto-positioning.

The following options are available for CHANGE REPLICATION SOURCE TO
statements:

o ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS = {OFF | LOCAL | uuid}

  Makes the replication channel assign a GTID to replicated
  transactions that do not have one, enabling replication from a source
  that does not use GTID-based replication, to a replica that does. For
  a multi-source replica, you can have a mix of channels that use
  ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS, and channels that do not. The
  default is OFF, meaning that the feature is not used.

  LOCAL assigns a GTID including the replica's own UUID (the
  server_uuid setting). uuid assigns a GTID including the specified
  UUID, such as the server_uuid setting for the replication source
  server. Using a nonlocal UUID lets you differentiate between
  transactions that originated on the replica and transactions that
  originated on the source, and for a multi-source replica, between
  transactions that originated on different sources. The UUID you
  choose only has significance for the replica's own use. If any of the
  transactions sent by the source do have a GTID already, that GTID is
  retained.

  Channels specific to Group Replication cannot use
  ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS, but an asynchronous
  replication channel for another source on a server instance that is a
  Group Replication group member can do so. In that case, do not
  specify the Group Replication group name as the UUID for creating the
  GTIDs.

  To set ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS to LOCAL or uuid, the
  replica must have gtid_mode=ON set, and this cannot be changed
  afterwards. This option is for use with a source that has binary log
  file position based replication, so SOURCE_AUTO_POSITION=1 cannot be
  set for the channel. Both the replication SQL thread and the
  replication I/O (receiver) thread must be stopped before setting this
  option.

  *Important*:

  A replica set up with ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS on any
  channel cannot be promoted to replace the replication source server
  in the event that a failover is required, and a backup taken from the
  replica cannot be used to restore the replication source server. The
  same restriction applies to replacing or restoring other replicas
  that use ASSIGN_GTIDS_TO_ANONYMOUS_TRANSACTIONS on any channel.

  For further restrictions and information, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-gtids-assign-anon
  .html.

o GET_SOURCE_PUBLIC_KEY = {0|1}

  Enables RSA key pair-based password exchange by requesting the public
  key from the source. The option is disabled by default.

  This option applies to replicas that authenticate with the
  caching_sha2_password authentication plugin. For connections by
  accounts that authenticate using this plugin, the source does not
  send the public key unless requested, so it must be requested or
  specified in the client. If SOURCE_PUBLIC_KEY_PATH is given and
  specifies a valid public key file, it takes precedence over
  GET_SOURCE_PUBLIC_KEY. If you are using a replication user account
  that authenticates with the caching_sha2_password plugin (the
  default), and you are not using a secure connection, you must specify
  either this option or the SOURCE_PUBLIC_KEY_PATH option to provide
  the RSA public key to the replica.

o GTID_ONLY = {0|1}

  Stops the replication channel persisting file names and file
  positions in the replication metadata repositories. GTID_ONLY is
  disabled by default for asynchronous replication channels, but is
  enabled by default for Group Replication channels, for which it
  cannot be disabled.

  For replication channels with this setting, in-memory file positions
  are still tracked, and file positions can still be observed for
  debugging purposes in error messages and through interfaces such as
  SHOW REPLICA STATUS statements (where they are shown as being invalid
  if they are out of date). However, the writes and reads required to
  persist and check the file positions are avoided in situations where
  GTID-based replication does not actually require them, including the
  transaction queuing and application process.

  This option can be used only if both the replication SQL (applier)
  thread and replication I/O (receiver) thread are stopped. To set
  GTID_ONLY = 1 for a replication channel, GTIDs must be in use on the
  server (gtid_mode = ON), and row-based binary logging must be in use
  on the source (statement-based replication is not supported). The
  options REQUIRE_ROW_FORMAT = 1 and SOURCE_AUTO_POSITION = 1 must be
  set for the replication channel.

  When GTID_ONLY = 1 is set, the replica uses
  replica_parallel_workers=1 if that system variable is set to zero for
  the server, so it is always technically a multi-threaded applier.
  This is because a multi-threaded applier uses saved positions rather
  than the replication metadata repositories to locate the start of a
  transaction that it needs to reapply.

  If you disable GTID_ONLY after setting it, the existing relay logs
  are deleted and the existing known binary log file positions are
  persisted, even if they are stale. The file positions for the binary
  log and relay log in the replication metadata repositories might be
  invalid, and a warning is returned if this is the case. Provided that
  SOURCE_AUTO_POSITION is still enabled, GTID auto-positioning is used
  to provide the correct positioning.

  If you also disable SOURCE_AUTO_POSITION, the file positions for the
  binary log and relay log in the replication metadata repositories are
  used for positioning if they are valid. If they are marked as
  invalid, you must provide a valid binary log file name and position
  (SOURCE_LOG_FILE and SOURCE_LOG_POS). If you also provide a relay log
  file name and position (RELAY_LOG_FILE and RELAY_LOG_POS), the relay
  logs are preserved and the applier position is set to the stated
  position. GTID auto-skip ensures that any transactions already
  applied are skipped even if the eventual applier position is not
  correct.

o IGNORE_SERVER_IDS = (server_id_list)

  Makes the replica ignore events originating from the specified
  servers. The option takes a comma-separated list of 0 or more server
  IDs. Log rotation and deletion events from the servers are not
  ignored, and are recorded in the relay log.

  In circular replication, the originating server normally acts as the
  terminator of its own events, so that they are not applied more than
  once. Thus, this option is useful in circular replication when one of
  the servers in the circle is removed. Suppose that you have a
  circular replication setup with 4 servers, having server IDs 1, 2, 3,
  and 4, and server 3 fails. When bridging the gap by starting
  replication from server 2 to server 4, you can include
  IGNORE_SERVER_IDS = (3) in the CHANGE REPLICATION SOURCE TO statement
  that you issue on server 4 to tell it to use server 2 as its source
  instead of server 3. Doing so causes it to ignore and not to
  propagate any statements that originated with the server that is no
  longer in use.

  If IGNORE_SERVER_IDS contains the server's own ID and the server was
  started with the --replicate-same-server-id option enabled, an error
  results.

  The source metadata repository and the output of SHOW REPLICA STATUS
  provide the list of servers that are currently ignored. For more
  information, see
  https://dev.mysql.com/doc/refman/8.4/en/replica-logs-status.html, and
  [HELP SHOW REPLICA STATUS].

  If a CHANGE REPLICATION SOURCE TO statement is issued without
  IGNORE_SERVER_IDS, any existing list is preserved. To clear the list
  of ignored servers, it is necessary to use the option with an empty
  list, like this:

CHANGE REPLICATION SOURCE TO IGNORE_SERVER_IDS = ();

  RESET REPLICA ALL also clears IGNORE_SERVER_IDS.

  When global transaction identifiers (GTIDs) are used for replication,
  transactions that have already been applied are automatically
  ignored. Because of this, IGNORE_SERVER_IDS is not compatible with
  gtid_mode=ON. If gtid_mode is ON, CHANGE REPLICATION SOURCE TO with a
  non-empty IGNORE_SERVER_IDS list is rejected with an error. Likewise,
  if any existing replication channel was created with a list of server
  IDs to be ignored, SET gtid_mode=ON is also rejected. Before starting
  GTID-based replication, check for and clear any ignored server ID
  lists on the servers involved; you can do this by checking the output
  from SHOW REPLICA STATUS. In such cases, you can clear the list by
  issuing CHANGE REPLICATION SOURCE TO with an empty list of server IDs
  as shown previously.

o NETWORK_NAMESPACE = 'namespace'

  The network namespace to use for TCP/IP connections to the
  replication source server or, if the MySQL communication stack is in
  use, for Group Replication's group communication connections. The
  maximum length of the string value is 64 characters. If this option
  is omitted, connections from the replica use the default (global)
  namespace. On platforms that do not implement network namespace
  support, failure occurs when the replica attempts to connect to the
  source. For information about network namespaces, see
  https://dev.mysql.com/doc/refman/8.4/en/network-namespace-support.htm
  l.

o PRIVILEGE_CHECKS_USER = {NULL | 'account'}

  Names a user account that supplies a security context for the
  specified channel. NULL, which is the default, means no security
  context is used.

  The user name and host name for the user account must follow the
  syntax described in
  https://dev.mysql.com/doc/refman/8.4/en/account-names.html, and the
  user must not be an anonymous user (with a blank user name) or the
  CURRENT_USER. The account must have the REPLICATION_APPLIER
  privilege, plus the required privileges to execute the transactions
  replicated on the channel. For details of the privileges required by
  the account, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-privilege-checks.
  html. When you restart the replication channel, the privilege checks
  are applied from that point on. If you do not specify a channel and
  no other channels exist, the statement is applied to the default
  channel.

  The use of row-based binary logging is strongly recommended when
  PRIVILEGE_CHECKS_USER is set, and you can set REQUIRE_ROW_FORMAT to
  enforce this. For example, to start privilege checks on the channel
  channel_1 on a running replica, issue the following statements:

STOP REPLICA FOR CHANNEL 'channel_1';

CHANGE REPLICATION SOURCE TO
    PRIVILEGE_CHECKS_USER = 'user'@'host',
    REQUIRE_ROW_FORMAT = 1,
    FOR CHANNEL 'channel_1';

START REPLICA FOR CHANNEL 'channel_1';

o RELAY_LOG_FILE = 'relay_log_file' , RELAY_LOG_POS = 'relay_log_pos'

  The relay log file name, and the location in that file, at which the
  replication SQL thread begins reading from the replica's relay log
  the next time the thread starts. RELAY_LOG_FILE can use either an
  absolute or relative path, and uses the same base name as
  SOURCE_LOG_FILE. The maximum length of the string value is 511
  characters.

  A CHANGE REPLICATION SOURCE TO statement using RELAY_LOG_FILE,
  RELAY_LOG_POS, or both options can be executed on a running replica
  when the replication SQL (applier) thread is stopped. Relay logs are
  preserved if at least one of the replication applier thread and the
  replication I/O (receiver) thread is running. If both threads are
  stopped, all relay log files are deleted unless at least one of
  RELAY_LOG_FILE or RELAY_LOG_POS is specified. For the Group
  Replication applier channel (group_replication_applier), which only
  has an applier thread and no receiver thread, this is the case if the
  applier thread is stopped, but with that channel you cannot use the
  RELAY_LOG_FILE and RELAY_LOG_POS options.

o REQUIRE_ROW_FORMAT = {0|1}

  Permits only row-based replication events to be processed by the
  replication channel. This option prevents the replication applier
  from taking actions such as creating temporary tables and executing
  LOAD DATA INFILE requests, which increases the security of the
  channel. The REQUIRE_ROW_FORMAT option is disabled by default for
  asynchronous replication channels, but it is enabled by default for
  Group Replication channels, and it cannot be disabled for them. For
  more information, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-privilege-checks.
  html.

o REQUIRE_TABLE_PRIMARY_KEY_CHECK = {STREAM | ON | OFF | GENERATE}

  This option lets a replica set its own policy for primary key checks,
  as follows:

  o ON: The replica sets sql_require_primary_key = ON; any replicated
    CREATE TABLE or ALTER TABLE statement must result in a table that
    contains a primary key.

  o OFF: The replica sets sql_require_primary_key = OFF; no replicated
    CREATE TABLE or ALTER TABLE statement is checked for the presence
    of a primary key.

  o STREAM: The replica uses whatever value of sql_require_primary_key
    is replicated from the source for each transaction. This is the
    default value, and the default behavior.

  o GENERATE: Causes the replica to generate an invisible primary key
    for any InnoDB table that, as replicated, lacks a primary key. See
    https://dev.mysql.com/doc/refman/8.4/en/create-table-gipks.html,
    for more information.

    GENERATE is not compatible with Group Replication; you can use ON,
    OFF, or STREAM.

  A divergence based on the presence of a generated invisible primary
  key solely on a source or replica table is supported by MySQL
  Replication as long as the source supports GIPKs and the replica uses
  MySQL version 8.0.32 or later. If you use GIPKs on a replica with the
  source using an earlier version of MySQL, such divergences in schema,
  other than the extra GIPK on the replica, are not supported and may
  result in replication errors.

  For multisource replication, setting REQUIRE_TABLE_PRIMARY_KEY_CHECK
  to ON or OFF lets the replica normalize behavior across replication
  channels for different sources, and to keep a consistent setting for
  sql_require_primary_key. Using ON safeguards against the accidental
  loss of primary keys when multiple sources update the same set of
  tables. Using OFF lets sources that can manipulate primary keys to
  work alongside sources that cannot.

  In the case of multiple replicas, when
  REQUIRE_TABLE_PRIMARY_KEY_CHECK is set to GENERATE, the generated
  invisible primary key added by a given replica is independent of any
  such key added on any other replica. This means that, if generated
  invisible primary keys are in use, the values in the generated
  primary key columns on different replicas are not guaranteed to be
  the same. This may be an issue when failing over to such a replica.

  When PRIVILEGE_CHECKS_USER is NULL (the default), the user account
  does not need administration level privileges to set restricted
  session variables. Setting this option to a value other than NULL
  means that, when REQUIRE_TABLE_PRIMARY_KEY_CHECK is ON, OFF, or
  GENERATE, the user account does not require session administration
  level privileges to set restricted session variables such as
  sql_require_primary_key, avoiding the need to grant the account such
  privileges. For more information, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-privilege-checks.
  html.

o SOURCE_AUTO_POSITION = {0|1}

  Makes the replica attempt to connect to the source using the
  auto-positioning feature of GTID-based replication, rather than a
  binary log file based position. This option is used to start a
  replica using GTID-based replication. The default is 0, meaning that
  GTID auto-positioning and GTID-based replication are not used. This
  option can be used with CHANGE REPLICATION SOURCE TO only if both the
  replication SQL (applier) thread and replication I/O (receiver)
  thread are stopped.

  Both the replica and the source must have GTIDs enabled
  (GTID_MODE=ON, ON_PERMISSIVE, or OFF_PERMISSIVE on the replica, and
  GTID_MODE=ON on the source). SOURCE_LOG_FILE, SOURCE_LOG_POS,
  RELAY_LOG_FILE, and RELAY_LOG_POS cannot be specified together with
  SOURCE_AUTO_POSITION = 1. If multi-source replication is enabled on
  the replica, you need to set the SOURCE_AUTO_POSITION = 1 option for
  each applicable replication channel.

  With SOURCE_AUTO_POSITION = 1 set, in the initial connection
  handshake, the replica sends a GTID set containing the transactions
  that it has already received, committed, or both. The source responds
  by sending all transactions recorded in its binary log whose GTID is
  not included in the GTID set sent by the replica. This exchange
  ensures that the source only sends the transactions with a GTID that
  the replica has not already recorded or committed. If the replica
  receives transactions from more than one source, as in the case of a
  diamond topology, the auto-skip function ensures that the
  transactions are not applied twice. For details of how the GTID set
  sent by the replica is computed, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-gtids-auto-positi
  oning.html.

  If any of the transactions that should be sent by the source have
  been purged from the source's binary log, or added to the set of
  GTIDs in the gtid_purged system variable by another method, the
  source sends the error ER_SOURCE_HAS_PURGED_REQUIRED_GTIDS
  (https://dev.mysql.com/doc/mysql-errors/8.4/en/server-error-reference
  .html#error_er_source_has_purged_required_gtids) to the replica, and
  replication does not start. The GTIDs of the missing purged
  transactions are identified and listed in the source's error log in
  the warning message ER_FOUND_MISSING_GTIDS
  (https://dev.mysql.com/doc/mysql-errors/8.4/en/server-error-reference
  .html#error_er_found_missing_gtids). Also, if during the exchange of
  transactions it is found that the replica has recorded or committed
  transactions with the source's UUID in the GTID, but the source
  itself has not committed them, the source sends the error
  ER_REPLICA_HAS_MORE_GTIDS_THAN_SOURCE
  (https://dev.mysql.com/doc/mysql-errors/8.4/en/server-error-reference
  .html#error_er_replica_has_more_gtids_than_source) to the replica and
  replication does not start. For information on how to handle these
  situations, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-gtids-auto-positi
  oning.html.

  You can see whether replication is running with GTID auto-positioning
  enabled by checking the Performance Schema
  replication_connection_status table or the output of SHOW REPLICA
  STATUS. Disabling the SOURCE_AUTO_POSITION option again makes the
  replica revert to file-based replication.

o SOURCE_BIND = 'interface_name'

  Determines which of the replica's network interfaces is chosen for
  connecting to the source, for use on replicas that have multiple
  network interfaces. Specify the IP address of the network interface.
  The maximum length of the string value is 255 characters.

  The IP address configured with this option, if any, can be seen in
  the Source_Bind column of the output from SHOW REPLICA STATUS. In the
  source metadata repository table mysql.slave_master_info, the value
  can be seen as the Source_bind column. The ability to bind a replica
  to a specific network interface is also supported by NDB Cluster.

o SOURCE_COMPRESSION_ALGORITHMS = 'algorithm[,algorithm][,algorithm]'

  Specifies one, two, or three of the permitted compression algorithms
  for connections to the replication source server, separated by
  commas. The maximum length of the string value is 99 characters. The
  default value is uncompressed.

  The available algorithms are zlib, zstd, and uncompressed, the same
  as for the protocol_compression_algorithms system variable. The
  algorithms can be specified in any order, but it is not an order of
  preference - the algorithm negotiation process attempts to use zlib,
  then zstd, then uncompressed, if they are specified.

  The value of SOURCE_COMPRESSION_ALGORITHMS applies only if the
  replica_compressed_protocol system variable is disabled. If
  replica_compressed_protocol is enabled, it takes precedence over
  SOURCE_COMPRESSION_ALGORITHMS and connections to the source use zlib
  compression if both source and replica support that algorithm. For
  more information, see
  https://dev.mysql.com/doc/refman/8.4/en/connection-compression-contro
  l.html.

  Binary log transaction compression is activated by the
  binlog_transaction_compression system variable, and can also be used
  to save bandwidth. If you do this in combination with connection
  compression, connection compression has less opportunity to act on
  the data, but can still compress headers and those events and
  transaction payloads that are uncompressed. For more information on
  binary log transaction compression, see
  https://dev.mysql.com/doc/refman/8.4/en/binary-log-transaction-compre
  ssion.html.

o SOURCE_CONNECT_RETRY = interval

  Specifies the interval in seconds between the reconnection attempts
  that the replica makes after the connection to the source times out.
  The default interval is 60.

  The number of attempts is limited by the SOURCE_RETRY_COUNT option.
  If both the default settings are used, the replica waits 60 seconds
  between reconnection attempts (SOURCE_CONNECT_RETRY=60), and keeps
  attempting to reconnect at this rate for 10 minutes
  (SOURCE_RETRY_COUNT=10). These values are recorded in the source
  metadata repository and shown in the
  replication_connection_configuration Performance Schema table.

o SOURCE_CONNECTION_AUTO_FAILOVER = {0|1}

  Activates the asynchronous connection failover mechanism for a
  replication channel if one or more alternative replication source
  servers are available (so when there are multiple MySQL servers or
  groups of servers that share the replicated data). The default is 0,
  meaning that the mechanism is not activated. For full information and
  instructions to set up this feature, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-asynchronous-conn
  ection-failover-replica.html.

  The asynchronous connection failover mechanism takes over after the
  reconnection attempts controlled by SOURCE_CONNECT_RETRY and
  SOURCE_RETRY_COUNT are exhausted. It reconnects the replica to an
  alternative source chosen from a specified source list, which you can
  manage using the functions
  asynchronous_connection_failover_add_source() and
  asynchronous_connection_failover_delete_source(). To add and remove
  managed groups of servers, use
  asynchronous_connection_failover_add_managed() and
  asynchronous_connection_failover_delete_managed() instead. For more
  information, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-asynchronous-conn
  ection-failover.html.

  *Important*:

   1. You can only set SOURCE_CONNECTION_AUTO_FAILOVER = 1 when GTID
      auto-positioning is in use (SOURCE_AUTO_POSITION = 1).

   2. When you set SOURCE_CONNECTION_AUTO_FAILOVER = 1, set
      SOURCE_RETRY_COUNT and SOURCE_CONNECT_RETRY to minimal numbers
      that just allow a few retry attempts with the same source, in
      case the connection failure is caused by a transient network
      outage. Otherwise the asynchronous connection failover mechanism
      cannot be activated promptly. Suitable values are
      SOURCE_RETRY_COUNT=3 and SOURCE_CONNECT_RETRY=10, which make the
      replica retry the connection 3 times with 10-second intervals
      between.

   3. When you set SOURCE_CONNECTION_AUTO_FAILOVER = 1, the replication
      metadata repositories must contain the credentials for a
      replication user account that can be used to connect to all the
      servers on the source list for the replication channel. The
      account must also have SELECT permissions on the Performance
      Schema tables. These credentials can be set using the CHANGE
      REPLICATION SOURCE TO statement with the SOURCE_USER and
      SOURCE_PASSWORD options. For more information, see
      https://dev.mysql.com/doc/refman/8.4/en/replication-asynchronous-
      connection-failover.html.

   4. When you set SOURCE_CONNECTION_AUTO_FAILOVER = 1, asynchronous
      connection failover for replicas is automatically activated if
      this replication channel is on a Group Replication primary in a
      group in single-primary mode. With this function active, if the
      primary that is replicating goes offline or into an error state,
      the new primary starts replication on the same channel when it is
      elected. If you want to use the function, this replication
      channel must also be set up on all the secondary servers in the
      replication group, and on any new joining members. (If the
      servers are provisioned using MySQL's clone functionality, this
      all happens automatically.) If you do not want to use the
      function, disable it by using the
      group_replication_disable_member_action() function to disable the
      Group Replication member action
      mysql_start_failover_channels_if_primary, which is enabled by
      default. For more information, see
      https://dev.mysql.com/doc/refman/8.4/en/replication-asynchronous-
      connection-failover-replica.html.

o SOURCE_DELAY = interval

  Specifies how many seconds behind the source the replica must lag. An
  event received from the source is not executed until at least
  interval seconds later than its execution on the source. interval
  must be a nonnegative integer in the range from 0 to 231−1. The
  default is 0. For more information, see
  https://dev.mysql.com/doc/refman/8.4/en/replication-delayed.html.

  A CHANGE REPLICATION SOURCE TO statement using the SOURCE_DELAY
  option can be executed on a running replica when the replication SQL
  thread is stopped.

o SOURCE_HEARTBEAT_PERIOD = interval

  Controls the heartbeat interval, which stops the connection timeout
  occurring in the absence of data if the connection is still good. A
  heartbeat signal is sent to the replica after that number of seconds,
  and the waiting period is reset whenever the source's binary log is
  updated with an event. Heartbeats are therefore sent by the source
  only if there are no unsent events in the binary log file for a
  period longer than this.

  The heartbeat interval interval is a decimal value having the range 0
  to 4294967 seconds and a resolution in milliseconds; the smallest
  nonzero value is 0.001. Setting interval to 0 disables heartbeats
  altogether. The heartbeat interval defaults to half the value of the
  replica_net_timeout system variable. It is recorded in the source
  metadata repository and shown in the
  replication_connection_configuration Performance Schema table.

  The replica_net_timeout system variable specifies the number of
  seconds that the replica waits for either more data or a heartbeat
  signal from the source, before the replica considers the connection
  broken, aborts the read, and tries to reconnect. The default value is
  60 seconds (one minute). Note that a change to the value or default
  setting of replica_net_timeout does not automatically change the
  heartbeat interval, whether that has been set explicitly or is using
  a previously calculated default. A warning is issued if you set the
  global value of replica_net_timeout to a value less than that of the
  current heartbeat interval. If replica_net_timeout is changed, you
  must also issue CHANGE REPLICATION SOURCE TO to adjust the heartbeat
  interval to an appropriate value so that the heartbeat signal occurs
  before the connection timeout. If you do not do this, the heartbeat
  signal has no effect, and if no data is received from the source, the
  replica can make repeated reconnection attempts, creating zombie dump
  threads.

o SOURCE_HOST = 'host_name'

  The host name or IP address of the replication source server. The
  replica uses this to connect to the source. The maximum length of the
  string value is 255 characters.

  If you specify SOURCE_HOST or SOURCE_PORT, the replica assumes that
  the source server is different from before (even if the option value
  is the same as its current value.) In this case, the old values for
  the source's binary log file name and position are considered no
  longer applicable, so if you do not specify SOURCE_LOG_FILE and
  SOURCE_LOG_POS in the statement, SOURCE_LOG_FILE='' and
  SOURCE_LOG_POS=4 are silently appended to it.

  Setting SOURCE_HOST='' (that is, setting its value explicitly to an
  empty string) is not the same as not setting SOURCE_HOST at all.
  Trying to set SOURCE_HOST to an empty string fails with an error.

o SOURCE_LOG_FILE = 'source_log_name', SOURCE_LOG_POS = source_log_pos

  The binary log file name, and the location in that file, at which the
  replication I/O (receiver) thread begins reading from the source's
  binary log the next time the thread starts. Specify these options if
  you are using binary log file position based replication.

  SOURCE_LOG_FILE must include the numeric suffix of a specific binary
  log file that is available on the source server, for example,
  SOURCE_LOG_FILE='binlog.000145'. The maximum length of the string
  value is 511 characters.

  SOURCE_LOG_POS is the numeric position for the replica to start
  reading in that file. SOURCE_LOG_POS=4 represents the start of the
  events in a binary log file.

  If you specify either of SOURCE_LOG_FILE or SOURCE_LOG_POS, you
  cannot specify SOURCE_AUTO_POSITION = 1, which is for GTID-based
  replication.

  If neither of SOURCE_LOG_FILE or SOURCE_LOG_POS is specified, the
  replica uses the last coordinates of the replication SQL thread
  before CHANGE REPLICATION SOURCE TO was issued. This ensures that
  there is no discontinuity in replication, even if the replication SQL
  (applier) thread was late compared to the replication I/O (receiver)
  thread.

o SOURCE_PASSWORD = 'password'

  The password for the replication user account to use for connecting
  to the replication source server. The maximum length of the string
  value is 32 characters. If you specify SOURCE_PASSWORD, SOURCE_USER
  is also required.

  The password used for a replication user account in a CHANGE
  REPLICATION SOURCE TO statement is limited to 32 characters in
  length. Trying to use a password of more than 32 characters causes
  CHANGE REPLICATION SOURCE TO to fail.

  The password is masked in MySQL Server's logs, Performance Schema
  tables, and SHOW PROCESSLIST statements.

o SOURCE_PORT = port_num

  The TCP/IP port number that the replica uses to connect to the
  replication source server.

  *Note*:

  Replication cannot use Unix socket files. You must be able to connect
  to the replication source server using TCP/IP.

  If you specify SOURCE_HOST or SOURCE_PORT, the replica assumes that
  the source server is different from before (even if the option value
  is the same as its current value.) In this case, the old values for
  the source's binary log file name and position are considered no
  longer applicable, so if you do not specify SOURCE_LOG_FILE and
  SOURCE_LOG_POS in the statement, SOURCE_LOG_FILE='' and
  SOURCE_LOG_POS=4 are silently appended to it.

o SOURCE_PUBLIC_KEY_PATH = 'key_file_name'

  Enables RSA key pair-based password exchange by providing the path
  name to a file containing a replica-side copy of the public key
  required by the source. The file must be in PEM format. The maximum
  length of the string value is 511 characters.

  This option applies to replicas that authenticate with the
  sha256_password (deprecated) or caching_sha2_password authentication
  plugin. (For sha256_password, SOURCE_PUBLIC_KEY_PATH can be used only
  if MySQL was built using OpenSSL.) If you are using a replication
  user account that authenticates with the caching_sha2_password plugin
  (the default), and you are not using a secure connection, you must
  specify either this option or the GET_SOURCE_PUBLIC_KEY=1 option to
  provide the RSA public key to the replica.

o SOURCE_RETRY_COUNT = count

  Sets the maximum number of reconnection attempts that the replica
  makes after the connection to the source times out, as determined by
  the replica_net_timeout system variable. If the replica does need to
  reconnect, the first retry occurs immediately after the timeout. The
  default is 10 attempts.

  The interval between the attempts is specified by the
  SOURCE_CONNECT_RETRY option. If both the default settings are used,
  the replica waits 60 seconds between reconnection attempts
  (SOURCE_CONNECT_RETRY=60), and keeps attempting to reconnect at this
  rate for 10 minutes (SOURCE_RETRY_COUNT=10). A setting of 0 for
  SOURCE_RETRY_COUNT means that there is no limit on the number of
  reconnection attempts, so the replica keeps trying to reconnect
  indefinitely.

  The values for SOURCE_CONNECT_RETRY and SOURCE_RETRY_COUNT are
  recorded in the source metadata repository and shown in the
  replication_connection_configuration Performance Schema table.
  SOURCE_RETRY_COUNT supersedes the --master-retry-count server startup
  option.

o SOURCE_SSL = {0|1}

  Specify whether the replica encrypts the replication connection. The
  default is 0, meaning that the replica does not encrypt the
  replication connection. If you set SOURCE_SSL=1, you can configure
  the encryption using the SOURCE_SSL_xxx and SOURCE_TLS_xxx options.

  Setting SOURCE_SSL=1 for a replication connection and then setting no
  further SOURCE_SSL_xxx options corresponds to setting
  --ssl-mode=REQUIRED for the client, as described in
  https://dev.mysql.com/doc/refman/8.4/en/connection-options.html#encry
  pted-connection-options. With SOURCE_SSL=1, the connection attempt
  only succeeds if an encrypted connection can be established. A
  replication connection does not fall back to an unencrypted
  connection, so there is no setting corresponding to the
  --ssl-mode=PREFERRED setting for replication. If SOURCE_SSL=0 is set,
  this corresponds to --ssl-mode=DISABLED.

  *Important*:

  To help prevent sophisticated man-in-the-middle attacks, it is
  important for the replica to verify the server's identity. You can
  specify additional SOURCE_SSL_xxx options to correspond to the
  settings --ssl-mode=VERIFY_CA and --ssl-mode=VERIFY_IDENTITY, which
  are a better choice than the default setting to help prevent this
  type of attack. With these settings, the replica checks that the
  server's certificate is valid, and checks that the host name the
  replica is using matches the identity in the server's certificate. To
  implement one of these levels of verification, you must first ensure
  that the CA certificate for the server is reliably available to the
  replica, otherwise availability issues will result. For this reason,
  they are not the default setting.

o SOURCE_SSL_xxx, SOURCE_TLS_xxx

  Specify how the replica uses encryption and ciphers to secure the
  replication connection. These options can be changed even on replicas
  that are compiled without SSL support. They are saved to the source
  metadata repository, but are ignored if the replica does not have SSL
  support enabled. The maximum length of the value for the
  string-valued SOURCE_SSL_xxx and SOURCE_TLS_xxx options is 511
  characters, with the exception of SOURCE_TLS_CIPHERSUITES, for which
  it is 4000 characters.

  The SOURCE_SSL_xxx and SOURCE_TLS_xxx options perform the same
  functions as the --ssl-xxx and --tls-xxx client options described in
  https://dev.mysql.com/doc/refman/8.4/en/connection-options.html#encry
  pted-connection-options. The correspondence between the two sets of
  options, and the use of the SOURCE_SSL_xxx and SOURCE_TLS_xxx options
  to set up a secure connection, is explained in
  https://dev.mysql.com/doc/refman/8.4/en/replication-encrypted-connect
  ions.html.

o SOURCE_USER = 'user_name'

  The user name for the replication user account to use for connecting
  to the replication source server. The maximum length of the string
  value is 96 characters.

  For Group Replication, this account must exist on every member of the
  replication group. It is used for distributed recovery if the XCom
  communication stack is in use for the group, and also used for group
  communication connections if the MySQL communication stack is in use
  for the group. With the MySQL communication stack, the account must
  have the GROUP_REPLICATION_STREAM permission.

  It is possible to set an empty user name by specifying
  SOURCE_USER='', but the replication channel cannot be started with an
  empty user name. It is valid to set an empty SOURCE_USER user name
  and use the channel afterwards if you always provide user credentials
  using the START REPLICA statement or START GROUP_REPLICATION
  statement that starts the replication channel. This approach means
  that the replication channel always needs operator intervention to
  restart, but the user credentials are not recorded in the replication
  metadata repositories.

  *Important*:

  To connect to the source using a replication user account that
  authenticates with the caching_sha2_password plugin, you must either
  set up a secure connection as described in
  https://dev.mysql.com/doc/refman/8.4/en/replication-encrypted-connect
  ions.html, or enable the unencrypted connection to support password
  exchange using an RSA key pair. The caching_sha2_password
  authentication plugin is the default for new users (see
  https://dev.mysql.com/doc/refman/8.4/en/caching-sha2-pluggable-authen
  tication.html). If the user account that you create or use for
  replication uses this authentication plugin, and you are not using a
  secure connection, you must enable RSA key pair-based password
  exchange for a successful connection. You can do this using either
  the SOURCE_PUBLIC_KEY_PATH option or the GET_SOURCE_PUBLIC_KEY=1
  option for this statement.

o SOURCE_ZSTD_COMPRESSION_LEVEL = level

  The compression level to use for connections to the replication
  source server that use the zstd compression algorithm. The permitted
  levels are from 1 to 22, with larger values indicating increasing
  levels of compression. The default level is 3.

  The compression level setting has no effect on connections that do
  not use zstd compression. For more information, see
  https://dev.mysql.com/doc/refman/8.4/en/connection-compression-contro
  l.html.

URL: https://dev.mysql.com/doc/refman/8.4/en/change-replication-source-to.html

